Abstract: A method and apparatus for connecting a rear trailer to a front trailer in a tandem tractor-trailer assembly in which a boom attachment for a lift truck is provided with a vertical rotary lock pin adapted to be secured to a mobile connector carrier for lifting, rotating and moving the carrier to a working position between the front and rear trailers. The boom lift attachment is designed to rotate the mobile connector carrier relative to the lift truck in order to accurately position the mobile connector carrier in a working space between the trailers and to move the carrier into locking engagement with the front trailer, prior to rearward movement of the front trailer to engage the kingpin of the rear trailer with the mobile connector carrier.